Propulsion means



April 2,1946.v j A. G.v FQRSVY'TH- 2,397,654'

v PnoPULsIoN MEANS 4l'zlled llay 2Q, 4 Sheets-Sheetl I' x 3mm ARcH/,s/uaamv/MM f'p/z'sym;

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April 2,1946. A. G. FoRsYTH 2,397,554

PRoPULsIoN MEANS y Filed may 2o, 1942 4 .snepssheet 2 u lllllllllll Ap2, 1946. A. G. FoRsY'rH PRoPULsloN MEANS Fi led May 20,' 1942 A 4Sheets-Sheet 3 April 2, 1946.

A G. FORSYTH PROPULSION MEANS 4 Sheets-Sheet 4 Filed May 20, 1942 a 7 9.w w \\\\\\\\w.m.///f7/ f//Z// Patented Apr. 2, 1946 f UNITED y STAT-EsPATENT-formes y PROPULSION MEANS Archibald Graham Forsyth.' chem, Emana,usignor to The Falrey 'Aviation Company IlmitedHayes,' Middlesex County,4

Application May zo, 1942, serial No. sass and more particularly to amarine propulsion detheprime mover, itis, of course, possible to employthemas an auxiliary to a main prime mover,

vice employing the exhaust from combustion units as the effective forceproducing the propulsion for' such vessels.

In present-day warfare, where' it is necessary to land an invasion forceLonjthe shore of an where, for example, weight and draft are not ofgreat importance. v

Another object of the'invention is the provision of any explosion ietmarine propulsion deisland or thelike, it has been the practice-toemploy barges or scows. These have been propelled by marine screwpropellers or in some instances by airplane propellers. Each of thesesystems requiresthe use of a ratherlargev internal combustion engineland consequently the vessels do not, .in many instances, .have asufflciently shallow draft to avoid mines-'and the like which in manycases are anchored only a small distance below the surface of the water.Moreover, with such arrangements, the surprise element is endangeredbecause of theN- i`n otor throbbing which can be picked up bythe'sensitive detectors now employed by the defending forces. Also, ithas been demonstrated that invaaion'barges or the like propelled byairplane motors are vulnerable to attack and lare easily rendereduseless, one well-placed shot being sufficient to -put them out ofcommission 111e present invention has for its principal object theprovision of an explosion jet marine propulsion device which will avoidthese disadvantages. To accomplish the desired end the 'vice which maybe disposed on a shallow draft barge or thehlike insuch-manner as toprovide considerablespace for men, armament, and torpedoes, and in whichthe men may be wellprotected.

I Other objects of this invention will become more apparent from thefollowing'speciilcation and claims when read in the light of theaccompanying drawingain which: y

Figure 1 is across sectional view taken on the line l-l of Figure 2,illustrating one embodil ment of the invention. l

Figure 1A shows a modiflediform of hull bottom. 'l

Figure 2 is a side rangement of the propulsion units, supercharg'er andmotor.

Figure 3 is 'a side plan view of a modification the invention. Figure 4is'a. top plan view of the arrangement of the. propulsion units shown inFigure 3. v Figure 5 is a sectional elevation of one form of theinternal combustion unit employed in a0 carrying out this invention.

invention makes use of one orrmore combustion units whichsdirect'theforce` ofthe gases exploded therein against -thej water to propel theinvention is very silent in operation and is not 40 likely to bedetected by4 the instruments now used for such In accordance withanother object of the ,in-

vention a series of combustion units may be connected with means forsupplying air thereto.

suchas, for example. with a supercharg'er driven l from a small internalcombustion engine or the like.4 Means may be provided for maintainingthe air supply at a constant predetermined pressure. The combustionunits may also be selectively connected or disconnected with the airsupply so that one, or any combination of the umts may be operated atwill.

While lt i8 intended that the combusti@ units Figure 6 is a sectionalelevation of a modification of the Ainternadcombustion unit which may beemployed in carrying out the teaching of this invention. I

Figure 'l is a cross sectional view of. a detail -drawn to anv enlargedscale.

Figure 8 is an 'enlarged sectional 4view of the control valve shcwninFigure 8, illustrating automatic operating means for reversingthe valve.

Figure Qisasimilarviewshowingthe valve -auditsv operating means inreversed position.

Referring now specifically to the drawings and particularly to Figures 1and 2,y the vessel I,

which is preferably of the flat bottom variety combustion units andexpend their forces on the water to drive the craft.

While the air supplied to the` combustion units according to theinvention should function as 55 may be suppliedbyany number of devices,it is plan view of a preferred aradvantageously supplied by asupercharger 5 driven mechanically by a small internal combustion engine3. The supercharger has an air intake 1 controlled by a throttle (notshown) which in turn is operated by a boost control 9, thereby providingmeans for governing the air pressure in the manifold II to which the combustion units I3 are joined.

As shown in Figures 1 and 2 two manifolds II extend rearwardly from thesupercharger, one on eachside of the vessel, and a series of combustionunits I3 is connected to each manifold so that air under pressure issupplied to the units.

The explosion units I3 preferably are water jacketed as indicated at I5,the bent lower exhaust pipe ends I1 of the units projecting throughopenings 23 in the water jacket casing. These exhaust ends I1 of theunits may in turn be disposed within spaced streamlined longitudinallyextending hollow shrouds or casings I9, rigidly mounted upon the bottomof the boat hull I. Each of these casings is provided with a smallopening 2| formed in its forward end portion and each is completely openat its opposite end 25. Alternatively the boat hull bottom itself may beprovided with two longitudinal grooves in which the bent exhaust ends I1of the explosion units I3 may be disposed.

Water is employed as the cooling medium eirculated in the water jacketI5. A motor driven water pump 29 has an inlet port 30 connected to theoutside of the hull. The pump 29 circulates water through conduits 3|and 3l' to the water jacket, the water finally' escaping through theoutlet pipe 33.

In Figure -5 I have shown a longitudinal cross sectional view of onetype of unit, which is provided with a forwardly opening or intakechamber 35 and a rearwardly opening or explosion chamber 39. 'I'hecombustion units outer casings 49,

YVISI are provided with a plurality of apertures 42 permitting the waterwhich is circulated through the water jacket I5 to contact the outersurface of the-inner` casings 45, 49, thereby maintaining the unit at alow operating temperature. 'I'he chambers 35 and 39 are conjointlyshaped to constitute a Venturi tube at the throat of which is a valve 43by which the intake chamber 35 is separable from the explosion chamber39. As shown, the air intake chamber 35 is of less diameter at itsleading end than at its mid por-- tion and is contracted again towardsits rear end, while the explosion chamber 39 has -a restricted outlet at45 or may even be itself shaped to constitute a Venturi tube. A nozzle41 is provided through which `a jet of liquid fuel may be injected intothe explosion-chamber 29, and a spark plug 49 is used for` igniting theexplosive mixture. In order to periodically open the valve 43 to admitair from the intake chamber 35 to the explosion chamber 39, to injectliquid fuel into said explosion chamber 39, and to fire the explosivemixture in said chamber 39, compressed air is supplied by a pipe 5I froma suitable source (not shown). The now of this compressed air iscontrolled by an automatically operating piston' valve 53 -slidable inthe valve cylinder 55 in a boss 51 situated in the intake chamber 35.

The valve 43 between the intake and explosion chambers 35 and 39 issodium lled for cooling purposes and is opened automatically against theaction of a coiled spring 59 by compressed air ad` mitted from the pipe5I toa cylinder BI in the boss 51, the stem of the valve 43 beingfurnished with a piston 93 which is slidable in the cylinder 51 in whichit is housed. In the boss 51 are two` pairs of ports 55, 61 and 59, 1I(see also'Figures 8 and 9) leading from the valve cylinder 55, of

which the ports 55 and 51 are opposite one an- 'other and are connectedwith the compressed air supply pipe 5I and the 'cylinder 6Irespectively, and of which the ports 59 and 1I are opposite one anotherand are connected, respectively,

with the cylinder 6I and with a pipe 13 leading to the fuel injectionnozzle 41. The piston valve 53 has a peripheral groove 15 by which,accordr ing to the position of the said piston valve 53, the ports 55and 61 are put in communication with one another, as shown in Figure 8,and hence compressed air is admitted from the pipe 5I to the cylinder6I,'moves the piston 53 against the action of thespring 59 and opens thevalve 43 between the intake and explosion chambers 35 and 39, or,alternately as shown'in Figure 9, the ports 59 and 1I are put intocommunication with one another, and hence the valve 43 is' closed andthe air in the cylinder 5I is exhausted therefrom underl the iniiuenceof the spring 59, and is driven into the pipe 13.\ Actually, the airthus exhausted from the cylinder 5I is still under pressure, thoughreduced, and may be used for fuel injection purposes. Figure 7, part ofthe pipe 13 is surrounded by a chamber 11 to which a fuel supply pipe 19is connected, and said pipe 13 is formed as a Venhn ytube at that partthereof which is surrounded by the chamber 11 and has radial openings 9Iby which the chamber 11 communicates with saidl Venturi tube. Hence,when the peripheral groove 15 of the piston valve 53 establishescommunication between the ports 59 and 1I, as shown in Figure 9, airunder pressure flows along the pipe 13 suckingup fuel as it passesthrough said Venturi tube, and injects a jet of fuel through the nozzle41 into the explosion chamber 39.

In order that compressed air may be admitted to, and exhausted from, thecylinder 9| to open the valve 43 and allow it to be closed by its spring59, a cross pin 93 on the piston valve 53 is engaged by the bifurcatedend of a lever 95 pivoted at 91 on a lug 99 on the boss- 51, and the endof said lever remote from said bifurcation is formed with an arcuateslot 9|. On the lug 99 on the boss 51 a second lever 93 is pivoted at95,the pivot pin 95 passing through the arcuate slot 9| of the lever 95,and the upper end of said lever 93 is bifurcated to engage a cross pin91 on an extension 99 of the stem of the valve 43, while the lower endof said lever 93 is connected with the lower part of the lever 95 by atorsion springv 99.

When the valve 53 is in the position shown in Figure 8 compressed air isadmitted from |the pipe 5I to the cylinder 9i. and the valve 43 isopened;

the opening of the valve 43 moves the cross Din 91 to the left, from theposition shown in Figure v9,'thus swinging the lever 93 about its pivot95,

stressed and, when suiiiciently Vtensioned, acts on the lever 95 andturns the latter about its pivot 91 from the position shown in Figure 8,.to the t,

position shown in Figure 9, the extent of movement of said lever-.beinglimited by the engagement oi the pivot pin 95 in the arcuate slot 9l.

Thus the position ofthe valve 53 is reversed and To this end, as shownin in'myeependim-appiieauon, sensi No. 437.429,

connection is established between the ports esv and'll, compressed airis exhausted from the Y cylinder 8| as the valve 43 closes and fuel isinjected into the explosion chamber 33 as set forth above.

In the pathy of .the extension sa o f the siem of the valve 43 is amovable switclrblade |0| which,

forced into contact with thenxed switch blade |03. 'I'he switch |0|, |03is arranged in the pri-` mary circuit insofan ignition con m1, thefseeisprovided to sparkvthe explosion chambers. in any desired sequence.

As shown in'Figures 5 and 6, a lcasing 52 is provided which is mountedon the outer casing 4|,

4,at the moment when thevalve 43 seats itselff'is filed April 2, 1942,of which this application isa continuation'-in-part.`

. circularsdiskfmounted unsuitable bearings and ondary of which'isconnected 'as at |013 with the spark plug 49. Firing timing means (notshown) and secured thereto against water leakage. The

casing 52 extends over and 'includes within its walls the spark plug 43,the conduit 13, and portions of the pipes 5| and 13, and also portionsof electrical wires |05 and |03. Obviously, other means-may be employedto prevent short circuiting of the spark plug 40 and the switch |03,|03, by water contact. The means shown here is merely illustrative ofone form thereof.

'The operation of the device is quite apparent. The air which ismaintained at a predetermined pressure value in the manifold Il ispassed into the intake chamber. 3l when thevalve 43 is in closedposition. A charge of air under pressure is admitted to the explosionchamber 39 and the air .in said explosion chamber 30 and," when thevalve 43 is closed, the explosive mixture is o when the valve 43 isopened, fuel is injected into fired and the discharge through therestricted outlet 43 produces the propulsive eifect.

In the modification of the explosion chamber` shown in'Figure 6, theexplosion chamber 33 is shaped to constitute a Venturi tube at thethroat of which is disposed a rearwardly opening spring influencedvalve' to allow pressure to build of the valve |||,Lsaid valvev being'thereafter closed,thestem of the valve has mounted thereon a flange Illarranged in a cylinder III in the rear end of the unit and influencedbyv a spring H0 which tends, normally, to close said valve.;v

Hence, when the explosion takes place' in the forward part of theexplosionchamber 33' the valve I is forced back slishtly againsttheaction of its springl ||3, carrying with it the flange Ii.

The unseating 'of the valve permits theexploded gases to pass fromchamber 33' through the reduced portion 4l and the tubes Ifl'A to'reactagainst the water surrounding them and provides the propelling force formoving the vessel.

In the above description of themodified explosion chamber those elementswhich correspond to similar elements discussed in the nrst describedexplosion chamber have'been given identicalnumeral reference numbers,but are diiferentiated therefrom by the addition'of a prime mark.

While I have shown and described butltwo types oi internal rcombustionumts, other modincations of the umts may also be employed, such as, forexample, any one of several types of inrotatably secured to .the wall4oi? the explosion chamber.'

Inl order -to' increase or .decrease the speed' of 'the boat thevoperator merely rotates thevalve disk, ythereby rendering it possibleIor impossible for the air accumulated-in the-manifold pipe to pass intothe explosionchamber.

In Figures 3 and 4I have disclosed amodiii arrangement of the internalcombustion units.

As shown therein elongated manifolds extend v positeend. -In thismodincation no water pump is required, as the water circulates freelyabout the umts. The function and theory of operation of thismodification is as has been described above.`

I claim:

1. A marine propulsion device V'adapted vto be mounted within a boat andcomprising a plurality of spacedv combustion units, each of said unitshaving an Aair intake port, an explosion chamber, and an exhaust pipe,one' end of each of said exhaust pipes being connected with its'respective explosion chamber, the other end of said exhaustpipespassing through the -hull of said boat and being submerged in thewater, an air intake port formed in each unit, means. for. connectingsaid air intake portswith a supply of air under pres-` sure, an airchamber .-in each of said units, said air chambers being connected withsaid air inlet' ports, an air controlrvalve in each of said umtsdisposed intermediate the air inlet ports and vair chambers, anexpldsion chamber, means for-supplying an ignitable" gasto saidexplosion chamber',l -means for mixing said airand said gas in said`explositionv chamber, means for ignlting said mixed gases andexhausting the combustion product thereof through the water.

I. 2..A' marine propulsion device adapted to be mounted in a boat,comprising, a plurality of spaced'internal combustion units enclosedwithin,

a fluid-tight Jacket, a pump adapted to circulate a cooling mediumthrough said jacket, each of said units having an air intake port and anexmanifold pipe, said air intake ports adapted toy be connected withsaid manifold pipe, an air cham' ber in each of said units, valvespositioned intermediatevsaid air intake ports and said air chambers.means for' selectively operating said valves to permit or prevent sirfrom entering said air chambers, combustion chambers .in said units.

ternal combustion devices shown and described 'I5 means for supplying anignitable gasto said comsaid,exhaust pipes, against I bustion chambers,-means for mixing said air with said gas in said combustion chambers.means for igniting said mixed gases and exhausting the combustionproduct thereof through said exhaust end portions.

3. A marine propulsion device adapted to be mounted within a boat,comprising, a plurality of spaced internal combustion units enclosedWithin a fluid-tight jacketfa pump adapted to circulate a cooling mediumthrough said jacket, each of said units having an air intake port and anexhaust endV portion, said exhaust end portionsextending through saidliacket'and the hull of said boat below the Water line of said hull,means adapted to maintain air under constant pressure in a manifold.pipe, saidgair intake ports being adapted to be connected with saidmanifold pipe, an air chamber in each of said units, means for supplyingan ignitable gas to said combustion chamber, means for mixing said airwith said gasmeans for igniting said mixed gases, and exhausting thecombustion product thereof through said exhaust end portions, a casingsecuredto the exterior surface of said boat hull, said casing enclosingsaid exhaust end portions and being open at at least one of its ends.

4. A marine propulsion device as defined in claim 3, said casing havinga relatively small opening -in 4the other end.

5. A marine propulsion device adapted to be mounted within a boat,comprising, a plurality of spaced internal combustion units enclosedwithin a duid-tight jacket, a pump adapted to circulate a cooling mediumthrough said jacket, each of said units` having an air intake port and ian exhaust end portion, said exhaust end portions extending through saidjacket and the hull of said boat below the water line of said hull,means adapted to maintain air under constant pressure in a manifoldpipe, said air intake ports beingadapted to be connected with saidmanifold pipe, an air intake chamber in each of said units, a valvedisposed Within each of said units intermediate said air intake port andsaid air chamber, said valves being operable simultaneously orindependently. at the will of the operator to permit or prevent air fromentering said air chambers, a combustion chamber in each of said units,means for supplying said combustion chambers with an ignitable gas,automatic means within said unit for mixing said gas with said air,means for igniting said mixed gases, and exhausting the combustionproduct vthereof through said exhaust end portions, said exhaust endportions being enclosed within a hollow casing having one of its endsopen, the other of said ends having a substantially and relativelyreduced opening formed therein. and those portions of said exhaust endportions enclosed within said hollow casing being substantially arcuateshaped and extending longitudinally therein.

6. A marine propulsion device adapted tobe mounted within a boat,comprising, a plurality of manifold pipes, means adapted to maintain airl under constant pressure in said manifold pipes,

said manifold pipes being spaced from each other and disposed onopposite sides of the hull of said boat, a plurality of internalcombustion units spaced from each other and disposed in opposite sidesof the boat, said units being enclosed within a fluid-tight jacket, apump adapted to circulate a cooling medium through said jackets, each ofsaid units having an air intake port adapted to be connected with themanifold disposed on the same side of said boat, each of said unitshaving an air intake Chamber, a valve in each of said units positionedintermediate said manifold and saidair intake chamber, a combustionchamber in each of said units, avalve disposed between said air chamberand said combustion chamber, means for supplying an ignitable gas tosaid combustion chamber, means for automatically operating saidlast-said valve to permit the ignitable gas and air to mix, means forigniting said mixed gases and exhausting the combustion products thereofthrough an exhaust v.pipe connected with said combustion chamber,

said exhaust pipes extending through said jackets and said boat andbelow the Water line of said boat, said exhaust pipes being arcuateshapedand extending rearwardly, those exhaust pipes on each side of theboat being enclosed within y a casing secured to the exterior of saidhull and below the water line thereof, said casing being open at one ofits ends and having a'substantially reduced opening at the other of itsends.

'7. A marine propulsion device adapted to bemounted within a boat,comprising, means for y maintaining air under constant pressure in aplurality of manifold pipes, said manifold pipes -being'spaced from eachother and disposed on opposite sides of said boat, a plurality ofcombustion units spaced from each other and disposed on opposite sidesof the hull of said boat, said units being enclosed within uidtightjackets, a pump adapted to circulate a cooling medium through saidJackets, each of said units having an air intake port adapted to beconnected with a manifold disposed on the same side of said boat, eachof said units having an air intake chamber, a valve disposed in each ofsaid units and positioned intermediate said manifold and saidy saidcombustion chamber adapted to only be operated when said mixed gaseshave been ignited, said exhaust pipes extending throughsaid jackets andthe hull of said boat below the water line thereof.

8. A marine propulsion device as defined in claim 1, said internalcombustion units having a spring operating valve positioned intermediatethe combustion chamber and said exhaust end portions, said valve beingnormally in closed position, said valve moving to its open position uponignition of said mixed gases thereby permitting 'said gases to passthrough said exhaust end portions.

ARCHIBALD GRAHAM FoRsYTH.

